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Survey at a glance

To collect information on income, family type and employment, and how they change over a period of eight years.

Selection process

A representative sample of New Zealand addresses.

Population

Approximately 22,200 individuals in 11,500 households, and 7,500 children aged under 15 years.

Frequency

Original sample members (OSMs) are interviewed once a year. From the second interview, people who begin living with an OSM will also be interviewed, but only while they remain living with an OSM.

Results

Survey results are published as they come available.

The survey

What is the survey’s purpose?

SoFIE is New Zealand's first national survey designed to study income, family type and employment, and how these change over time. Interviewing for SoFIE began in October 2002. SoFIE is a longitudinal survey that Statistics New Zealand plans to run for eight waves (or interview cycles).

What is a longitudinal survey?

A longitudinal survey involves revisiting the same people or 'respondents' over time. This contrasts with a cross-sectional survey where different respondents are selected each time the survey is repeated. As a longitudinal survey, SoFIE will be able to build a dynamic picture, somewhat like a movie, of how individual and family circumstances and lifestyles change over time. A cross-sectional survey would only give a series of snapshots.

Who is included in this survey?

At wave one, 15,000 randomly-selected households were approached to take part in SoFIE. Our interviewers visited each of the addresses and asked for the names of every member of the household. Household members were then asked questions to see if they were eligible for the survey (for example the survey does not interview overseas visitors who intend to stay in New Zealand for less than 12 months).

All eligible household members who responded to this first wave of the survey became original survey members (OSMs). They will be asked to complete an interview for the eight waves of the survey, even if their household changes. Anyone who begins living with an OSM during the course of SoFIE will also be interviewed, but only for as long as they continue to live with an OSM.

How is the survey conducted?

At wave one, 15,000 randomly-selected households were approached to take part in SoFIE. Our interviewers visited each of the addresses and asked for the names of every member of the household. Household members were then asked questions to see if they were eligible for the survey (for example the survey does not interview overseas visitors who intend to stay in New Zealand for less than 12 months).

All eligible household members who responded to this first wave of the survey became original survey members (OSMs). They will be asked to complete an interview for the eight waves of the survey, even if their household changes. Anyone who begins living with an OSM during the course of SoFIE will also be interviewed, but only for as long as they continue to live with an OSM.

How will the information from this survey be used?

The information SoFIE gathers will assist in the development of a range of economic and social policies. The survey results will help the government and New Zealanders understand the factors that have the most impact on social and economic wellbeing over time (factors like educational qualifications, family situation, sources of income, and age). The resulting statistics can be used to answer questions such as:

What are the chances of people moving from one state to another – for example, from receiving a benefit to working part time?

Do higher educational qualifications predict movements from unemployment to employment for different age groups?

How long are spells of employment or unemployment for people of particular ages or family situations?

How frequent are events such as spells of low income?

What other longitudinal work is Statistics New Zealand involved in?

TheLongitudinal Immigration Survey: New Zealand is a partnership between the Department of Labour and Statistics New Zealand. In November 2001, Statistics NZ published a research report on analysing data from the Household Labour Force Survey in a longitudinal way, A Longitudinal Look at some Data of the Household Labour Force Survey.

Giving data

How often does this survey take place?

Original sample members are interviewed once a year over an eight year period from 2002 to 2010. From the second interview onwards, people who remain living with OSMs are also interviewed once a year.

How long will the interview take?

The entire interview takes about 40–50 minutes for each adult. For a child aged under 15 years, an adult answers on their behalf and the questions should only take one minute. An interviewer will arrange a convenient time to interview those members of your household who are aged 15 years and over. The interviewer is able to visit your household more than once, at your convenience, to ensure everyone completes an interview. The interviewer uses a laptop computer (with showcards for some answers) to record the answers.

What type of questions are asked in the survey?

Two questionnaires are used to collect information for SoFIE – the household questionnaire is answered by one person in each household and collects household characteristics. A personal questionnaire is completed with every original survey member aged 15 years and over. A slightly shorter version of the personal questionnaire is completed with any adult cohabiting with an original survey member adult from wave two onwards. Children aged under 15 years are not interviewed; instead, a nominated parent or other adult is asked questions about them.

The household questionnaire contains two modules of questions:

Household (for example, household type, family type)

Standard of living (for example, type of housing, appliances owned).

The personal questionnaire contains the following modules:

Demographics (for example age, country of birth)

Child (demographics about any child(ren) under 15 years residing in the household – answered by a nominated adult)

Labour market history (for example, age at first paid job)

Education (for example, highest qualification)

Family (for example, existence of partners, children)

Labour market (current activity – for example, details of employment)

Income (for example, from paid work, superannuation, government payments)

Contact (respondents contact details).

In wave two, four six and eight a module collecting type and value of assets and liabilities will be included. In waves three, five and seven a health module, collecting self-rated health status, incidence of chronic diseases, major health events, risk factors and health service use, will be included.

Does the use of laptops affect the security of my information?

Access to the interview system is controlled by a password. All interview data on the laptop is automatically stored in a form that would be meaningless without authorised access.

My obligations

Do I have to complete this questionnaire?

Under the Statistics Act 1975 you must provide the information requested by Statistics New Zealand. In the households selected, everyone aged 15 years and over takes part in an interview. Your help is vital and appreciated because responses from all kinds of people helps give us an accurate picture of New Zealanders' income and employment patterns. Your answers are important because they represent others like you.

How can I keep in touch if I move?

Your responses for the full eight years of the SoFIE are very important for the validity of the resulting statistics. If you move house, please email your new address to sofie@stats.govt.nz, or call us on 0800 104 744.

Will I be paid for providing information to Statistics New Zealand?

Providing information to Statistics New Zealand is a statutory obligation. There is no provision in the Statistics Act 1975 for people to be paid for providing information.

How is my privacy protected?

Only people authorised by the Statistics Act are allowed to see your individual information, and they must use it only for statistical purposes. Your information will be combined with information from other people to prepare summary statistics about groups. We make sure that no individual can ever be identified when the results are published. Individual details such as your name and address are not included in data used for analysis to ensure privacy.